1. Field of the Invention
The present invention relates to an endoscope system.
2. Description of the Related Art
For example, JP-A-2000-342533 discloses an endoscope system including an endoscope which has an imaging element emitting illumination light from a front end of an endoscope insertion unit and capturing an image of an observation area, and a control device which supplies the illumination light to the endoscope while being connected to the endoscope, and performs a calculation process on an imaging signal from the imaging element. In addition, recently, a technology of using a combination of a fluorescent substance and laser light as the illumination light of the endoscope has been put to practical use.
In such an endoscope system, in order to accurately examine an affected portion, a chromacity adjustment process is performed by correcting chromacity of a captured image to be the correct chromacity on the basis of a predetermined chromacity correction table. However, there is an individual difference in an optical characteristic of each endoscope and an optical characteristic of a control device to which the endoscope is connected. In addition, even when the uniform correction of the image signal output from the endoscope is attempted by the control device, it is difficult to perform the correction to be the correct chromacity at all times. Particularly, in the case of the illumination device obtained by combining the fluorescent substance with the laser light source, since the tone of the final observation image is determined by the delicate relationship of a difference in the light emission characteristic caused by the individual differences of the fluorescent substance or a difference in the light emission wavelength caused by the individual differences of the light source, when the endoscope connected to the control device is exchanged with another one, the tone of the captured image may be changed for each endoscope.
In addition, even when the correct chromacity adjustment is performed during the manufacture of the endoscope or the control device, the optical characteristic of the laser light source or the fluorescent substance may be changed over time in some cases. Generally, in the semiconductor light emitting element, there arises a variation in the optical characteristic such as a decrease in the light output in accordance with the time elapsed from the start of usage. For this reason, in the case where maintenance such as an exchange of a light source element is periodically performed, the operation needs to be performed under conditions where external light or temperature is managed. In addition, a device such as a reference color sample necessary for adjustment needs to be accommodated. Due to such inconvenience, in many cases, the maintenance is not performed by a user, but performed in the maker's factory after being transported thereto.